1. Field of the Invention
The present invention relates to iontophoretic drug delivery systems for transdermally delivering a drug or medicine to a patient, and more specifically relates to an iontophoretic drug delivery system wherein a control housing, having electrical control components therein, is removably mounted to a drug delivery patch.
2. Description of the Prior Art
Iontophoresis may be defined as the passing of chemicals through skin without mechanical puncturing. The chemicals to be infused are in the form of a solution of ions which are stored proximate to a small electrode placed on the surface of the skin. An electric field is produced by the electrode which acts on the charged chemical particles and causes them to diffuse through the skin.
The use of devices for iontophoretic transdermal delivery of drugs are known in the art. Reference to or disclosure of devices for transdermal delivery of drugs by application of electric current through the skin of a person or animal are shown in a number of U.S. patents including U.S. Pat. No. 4,820,263 which issued to Richard Spevak, et al. However, many of the known iontophoretic systems include a control unit which is distally located from the electrode structure that delivers the medication to a specific body location of an individual. The distally located control unit tends to be cumbersome to the individual being treated due to cables and connectors which are required to interconnect the electrode structure to the control system components. The conventional transdermal drug delivery systems, while somewhat portable in nature, were intended for use in a hospital or physician's office. Therefore, these systems are not readily used by patients outside of a supervised environment during the patient's normal daily activities.
Developments in the iontophoretic drug delivery industry have produced drug delivery systems (control unit and corresponding electrode patch) which are portable in nature. However, the control unit of these drug delivery systems are an integral part of the electrode patch structure. In addition, the control unit tends not to be readily separable from the patch which delivers the medicine. Other drug delivery units have been developed wherein the control portion is not integral with the patch. However, these detachable control portions tend to be difficult to properly couple to the patch and they are not entirely user friendly.